Fair Value (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value Disclosures [Abstract]

Recurring Fair Value Measures [Table Text Block]

	Fair Value as of September 30, 2018
Recurring Fair Value Measures	Level 1		Level 2		Level 3		Total
Millions
Assets
Investments (a)
Available-for-sale – Equity Securities		$12.7	—		—			$12.7
Available-for-sale – Corporate and Governmental Debt Securities	—			$8.3	—		8.3
Cash Equivalents	1.5		—		—		1.5
Total Fair Value of Assets		$14.2		$8.3	—			$22.5
Liabilities
Deferred Compensation (b)	—			$20.5	—			$20.5
U.S. Water Services Contingent Consideration (c)	—		—			$5.7	5.7
Total Fair Value of Liabilities	—			$20.5		$5.7		$26.2
Total Net Fair Value of Assets (Liabilities)		$14.2	$(12.2)		$(5.7)		$(3.7)

(a) Included in Other Investments on the Consolidated Balance Sheet.

(b) Included in Other Non-Current Liabilities on the Consolidated Balance Sheet.

(c)

Included in Other Current Liabilities on the Consolidated Balance Sheet.

	Fair Value as of December 31, 2017
Recurring Fair Value Measures	Level 1		Level 2		Level 3		Total
Millions
Assets
Investments (a)
Available-for-sale – Equity Securities		$10.2	—		—			$10.2
Available-for-sale – Corporate and Governmental Debt Securities	—			$8.9	—		8.9
Cash Equivalents	3.8		—		—		3.8
Total Fair Value of Assets		$14.0		$8.9	—			$22.9
Liabilities (b)
Deferred Compensation	—			$18.2	—			$18.2
U.S. Water Services Contingent Consideration	—		—			$5.4	5.4
Total Fair Value of Liabilities	—			$18.2		$5.4		$23.6
Total Net Fair Value of Assets (Liabilities)		$14.0	$(9.3)		$(5.4)		$(0.7)

(a) Included in Other Investments on the Consolidated Balance Sheet.

(b)

Included in Other Non-Current Liabilities on the Consolidated Balance Sheet.

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

Recurring Fair Value Measures
Activity in Level 3
Millions
Balance as of December 31, 2017		$5.4
Accretion	0.3
Balance as of September 30, 2018		$5.7

Financial Instruments [Table Text Block]

Financial Instruments	Carrying Amount	Fair Value
Millions
Long-Term Debt, Including Long-Term Debt Due Within One Year
September 30, 2018	$1,527.9	$1,557.6
December 31, 2017	$1,513.3	$1,627.6